Tor Messenger is an instant messaging client that sends messages over the Tor anonymity network. It is available for Linux, macOS, and Windows. Tor Messenger supports a variety of messaging networks and protocols including IRC, XMPP, Twitter, Google Talk, and others. In addition, off-the-recordencryption is built in.

In its default configuration, Tor Messenger only communicates via the encrypted off-the-record (OTR) protocol. This means that if you want to talk with someone who doesn't have a program capable of chatting over OTR, you won't be able to communicate with them. You can change this option by going into “Tools -> OTR Preferences” and unchecking “Require encryption,” but keep in mind this will send your conversations over plaintext so your instant messaging provider can see the message contents.

Tor Messenger is still in beta, which means that it may have reliability or functionality shortcomings. Use with caution.

When you first run Tor Messenger, you'll be presented with the following screen:

In most cases, you can choose the first option and click “Connect.” If you are in a censored or proxied environment—for example, if you are in a country where the government censors the Internet—the second “Configure” option will walk you through how to connect to Tor.

Once connected to Tor, all your Tor Messenger communications will be routed through the Tor network. This means that your location will be hidden from the service you're using. If you register your Tor Messenger account with a random username that you use only on Tor Messenger, you will also have good assurance of anonymity.

You will have the option to choose from a number of chat systems. For this guide, we will focus on XMPP (formerly known as Jabber). This will allow you to communicate with others who also use XMPP. (Likewise, choosing Twitter, Google Talk, IRC, or another system will allow you to communicate with others who also use that system. (Gchat users should note, though, that they will not be able to chat with users on other XMPP servers.) Click on XMPP, then click “Continue.”

Just like you would choose an email provider, you can choose your XMPP provider. There is no one right choice, but this server: jabber.calyxinstitute.org is a perfectly good one. So choose a username for your account and a server to connect to. If you are not signing in to an existing account and are creating a new account, check the “Create this new account on the server” box.

Click continue, choose an alias if desired, and click continue again. This alias can be a nickname or pseudonym that is shorter and easier to remember than your username and domain. On the following screen, you will be given the option to connect to this chat account every time Tor Messenger starts. Click “Done,” then “Connect.”

Type in your password once more, and click “OK.” You will now be connected to the XMPP server.

If your contact also supports Off-the-Record messaging, your messaging client will initiate an encrypted chat when you send them a message. Look for the closed lock icon in the top right of your chat window to ensure encryption is working.

At this point, you can verify the identity of your contact. This process is called key verification. You might want to do this to ensure that their encryption key has not been tampered with, or replaced with the key of someone else when your application downloaded it. This process is important to make sure that you are actually talking to the person you think you are talking to.

From the chat window, click on the lock icon and then click “Verify your contact's identity.”

You will see a list of different verification methods. Most clients support “Manual fingerprint verification,” so that is a good choice to start with.

For manual fingerprint verification, read your account’s fingerprint (the long series of digits after “Fingerprint for you”) out loud to your contact. Have them do the same, and make sure it matches up with long series of digits after “Purported fingerprint for...” It is best to do this in person or over the phone. No matter what, be sure to exchange fingerprints through a communication channel besides the account you are trying to verify.

Once you have verified that you each have the same fingerprints for each account, change the box that says “I have verified that this is in fact the correct fingerprint” to “Yes,” and click “Verify.”

The lock in the top right of your chat window should now change from orange to green. This indicates that your contact has been verified. If your contact at any point reinstalls their chat client, you will have to verify fingerprints again to confirm their identity.

Now that you know how to use Tor Messenger, try sending an encrypted chat to your friends with this instant messaging client.